The invention relates generally to the field of intraoperative nerve imaging and more specifically, to the field of optical design of compact high collection power imaging devices for fluorescence and white light imaging of myelin basic protein (MBP) nerve imaging agents during surgery.
Fluorescence imaging is used to highlight molecules and structures, not otherwise visible under white light illumination, and is an emerging technique for surgical guidance. By administering a molecular contrast agent to a patient, disease processes can be specifically labeled for visualization during clinical examination. In concert with white light imaging, fluorescence imaging captures movies of anatomy with tissue specific information, and provides the clinician with a macroscopic visualization of biology in its intact and native physiological state. It holds promise as a way for real time guidance for tumor resection, sentinel lymph node mapping, vasculature and tissue perfusion imaging, as well as early detection of colorectal cancer.
However, many technical challenges are still present as related to the targeted imaging of nerves. A targeted contrast agent for fluorescence guided surgical imaging of nerves must nominally feature several attributes: the ability to penetrate the blood nerve barrier, high selectivity to nerves, and near infrared fluorescence properties. One issue in imaging nerves is related to the light attenuation in tissue. The spectroscopic properties of the biological medium and the optical properties of the fluorescent contrast agent, which may overlap in the spectral range. Another issue is related to the physics of imaging, a challenge is light attenuation in the nerve tissue and the sensitivity of the imaging instrument at low light conditions.
Imaging of targeted agents requires higher sensitivity to detect low levels of the agent. Regardless of the dose orally, intravascularly, or otherwise administered to the patient, local concentrations of the contrast agent can be on the order of tens of nmol/L.
It is therefore desirable to provide a compact image guided system for intraoperative nerve imagining with high collection power for intraoperative nerve imaging.